1) To test whether exposure to radiofrequency exposure from a portable exposure device resulted in an increase in an electrosensitive subjects's symptom compared to sham exposure and
2) to determine whether electrosensitive probands could detect the active radiofrequency signal at greater than chance level.
Three (2 male, 1 female) subjects with self-diagnosed electromagnetic hypersensitivity were included. The tests were conducted in the home environments of the participants.
On the first day, two non-blinded open trials were conducted: one with radiofrequency exposure and one without (both subject and researcher were aware of the exposure status). Afterwards, 12 double-blind, randomized and counterbalanced trials were conducted consisting of 6 trials with radiofrequency exposure and 6 trials with sham exposure. Each trial ran for 105 minutes, starting with a 15 minutes baseline to assess the subject's symptoms prior to exposure. This was followed by a 30 minutes exposure/sham exposure accompanied by questions about symptoms and exposure status. Afterwards, symptoms were assessed in a 30 minutes post-exposure period. Finally, a 30 minutes rest closed the trial. The trials took part on three consecutive days.
|Distance between exposed object and exposure source||30 cm|
|Chamber||device was fully enclosed in a thermally insulated case|
|Setup||exposure device was situated in front or to the side of the subject depending on what was comfortable for the subject|
|Sham exposure||A sham exposure was conducted.|
No significant difference in symptom severity or exposure detection was found for any of the subjects between the two conditions (exposure and sham exposure). Belief of exposure strongly predicted symptom severity score for all subjects.